Several security issues were fixed in PHP.
It was discovered that PHP incorrectly handled certain stream metadata. A remote attacker could possibly use this issue to set arbitrary metadata. This issue only affected Ubuntu 14.04 LTS. (CVE-2016-10712)
19 March 2018
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in PHP.
It was discovered that PHP incorrectly handled certain stream metadata. A remote attacker could possibly use this issue to set arbitrary metadata. This issue only affected Ubuntu 14.04 LTS. (CVE-2016-10712)
It was discovered that PHP incorrectly handled the PHAR 404 error page. A remote attacker could possibly use this issue to conduct cross-site scripting (XSS) attacks. This issue only affected Ubuntu 16.04 LTS and Ubuntu 17.10. (CVE-2018-5712)
It was discovered that PHP incorrectly handled parsing certain HTTP responses. A remote attacker could use this issue to cause PHP to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2018-7584)
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In Ubuntu 16.04 LTS and Ubuntu 17.10, this update uses a new upstream release, which includes additional bug fixes.
In general, a standard system update will make all the necessary changes.